Barrett's esophagus is a condition in which cells lining the esophagus near the entrance to the stomach become abnormal due to exposure to stomach acid. Barrett's esophagus typically extends about 8 cm away from the stomach entrance. The condition is often a precursor of esophageal cancer, so detection of abnormal cells indicating not only esophageal cancer, but also Barrett's esophagus, is important.
Barrett's esophagus and esophageal cancer are diagnosed by visually inspecting the esophagus lining, collecting cells from the esophagus lining and subjecting them to cytological examination. Procedures for collecting the cells have been such that diagnosing Barrett's esophagus or esophageal cancer was quite expensive. When the esophagus lining was visually inspected, an endoscope was employed and the patient was anesthetized for the process. The visualization process enables the physician to determine the location of the cells in question. A cell collection device may then be inserted through the endoscope and engaged with the esophagus lining in the areas where the cells in question have been located.
Various devices for collecting cells have been proposed. Among these have been inflatable balloon-like elements that have been inserted into the esophagus through the endoscope, inflated and rubbed on the lining to collect the cells. The balloons were deflated for removal. These devices have not been completely satisfactory in collecting adequate numbers of cells for examination. Brushes have also been used to collect cells. Brushes have been effective to collect sufficient numbers of cells, but have been constructed so that they brushed the entire length of the esophagus during removal. This has been undesirable because cells collected from the region of the esophagus near the stomach entrance have been dislodged from the brush during extraction of the brush from the esophagus. Dislodging such cells not only reduced the number of cells available for examination but also deposited the cells in regions of the esophagus where abnormal cells did not exist.
The present invention provides a new and improved method and apparatus for collecting cells from the esophagus for cytological examination wherein the process of collecting the cells is relatively inexpensive, does not require use of an endoscope, or the like, for locating the region of the esophagus from which cells are to be obtained and wherein regions of the esophagus remote from the stomach are not contacted by cell collection devices.